Since the 1970s, the Fontan operation has been used to palliate a heterogeneous group of patients with single-ventricle physiology. With improvements in surgical technique and medical care, large numbers of women are now surviving to child-bearing years, and many desire pregnancy.1 Preconception counseling and management of pregnancy in women status post–Fontan palliation was initially uncharted territory. Recommendations were based primarily on expert opinion. Unfortunately, because of the diverse anatomic variation in women with congenital heart disease and variations in underlying risk factors, research in this highly complex patient population is not straightforward.

In this issue of Circulation: Cardiovascular Quality and Outcomes, Garcia-Ropero et al2 aim to conduct a systematic review of the literature published about pregnancy in women with prior Fontan surgery. Unfortunately, there are only 6 studies (2 from the same center with overlapping patient populations) describing outcomes during a 30-year time span. Acknowledging these limitations, the authors summarize information from 255 pregnancies in 133 women status post–Fontan palliation, which resulted in 115 live births. There were no maternal deaths reported, but complications included supraventricular arrhythmias, heart failure, premature delivery and small-for-gestational-age infants, and postpartum hemorrhage. This important article highlights the maternal and fetal risks of pregnancy in this unique patient population. However, the challenges in grouping the risks among a highly divergent, heterogeneous patient population with complex congenital heart disease are also apparent.

The Fontan palliation is used to palliate a variety of conditions characterized by only a single well-developed ventricle. Lesions palliated by this procedure include tricuspid atresia, pulmonary atresia with intact ventricular septum, hypoplastic left heart syndrome, double inlet left ventricle, unbalanced atrioventricular canal …